how do I write a function to do nothing?

I want to write a function that does nothing. the goal is to have a function do nothing so I can place it as a place holder for display code. so if a monitor is used mon.setTextScale() would change the scale, but if the teminal is used I can save the term API and this function into mon and mon.setTextScale() would do nothing as to not error if called.

Shouldn't this be as easy as writing

mon.setTextScale = function()
end

Or did you have any problems with something like that?

I thought so, but I am currently nowhere near a instance of minecraft with computercraft installed, or on a device to run minecraft on. That and I am currently coding something that that was needed on an android tablet